Are you a good mechanic or (like me) an OK 'fiddler' but not much use at anything serious?
Good with electrics (a real benefit with a fibreglass car
)?
Kept in a garage with power (It does make a difference being able to keep the battery charged and checking that 'sticky window when the weather is cr4p etc)?
Roughly where are you based (near someone that knows about Alps?)?
All relevant to running costs.
With my A310s I've had years when I haven't used them (this year is another one) so tiny costs, and in some years when I've used them I've had years of pretty much zero cost and in some years the most I've spent well under 1k (inc new rad and D/Shaft seal).
Obviously excluding standard servicing costs and tyres.
But I also know that anything serous could mean a tow truck and a couple of grand or £50 from ebay plus 50 labour.... depending if it's in need of a general Renault part or a rare genuine Alpine part.
If you're near Clee, Mr Sage, Mr Law or El Presidente Dell, then I'd suggest you visit them for a chat as they may know of decent cars for sale (or know the faults of a 'for sale' car).
The biggest issue with A610s & GTAs at the moment seems to be internal chassis rust which Clee looks to have 'well sussed' but there are others issues that would be seen by an experienced eye. Cooling system can be an issue (especially air-locks and the main pipes) and if you're not doing the work but trying to 'cheapskate' it, then it can be very very time consuming = costly if you're paying someone else. But that's the same with any car when you chase a fault.
Alpine A110, Renault Safrane 2.5dt, Hudson Kindred Spirit (Renault powered), transAlp (Honda) and Ducati Multistrada